Researchers have confirmed at least one tornado struck an area north of Belleville on Sunday evening, Environment Canada says.

Staff from the Northern Tornadoes Project and Western University and Environment Canada determined the long track of damage in the Marmora, Madoc and Actinolite area was “due to at least one tornado and downburst winds,” the weather agency said in an update Tuesday morning.

Researchers giving the storm a preliminary rating of EF-1, with peak winds nearing 175 kilometres per hour.

According to Environment Canada, homes and trees were damaged in areas that include Havelock, Marmora, Madoc and Tweed, which are east of Peterborough and north of Belleville.

The weather agency Tuesday morning reported extensive damage along a path from Round Lake, Ont. east through Marmora and Madoc, to east of Actinolite. That includes a flipped trailer in Rockdale with multiple injuries reported, extensive tree damage, homes damaged with the roofs partially removed, barns destroyed, and hydro lines and poles down on roads, including Highway 7.

The municipality of Tweed has declared a state of emergency. A reception centre is open at the Tweed Library at 230 Metcalf St., with bottled water. Power is available.

The severe thunderstorms, which triggered tornado warnings across the region, left more than 26,000 customers without power. Power has been restored to most of those customers, according to Hydro One.

The storms also brought heavy rainfall to much of eastern Ontario. Brockville, Ont. received nearly 85 millimetres of rain, researchers said. Dunrobin and Stittsville, in Ottawa’s west end, received 47 and 42 millimetres respectively.